How to I deal with Illinois correction notice?

I received a letter from the Illinois Department of Revenue saying I owe more money. They don't take into account the payment I made with my TT return or the part of my 2016 refund which my accountant applied to my estimated taxes for 2017. The sum of those two amounts is what they are asking me to pay. Does Illinois really not recognize the two payments I made? Are they just hoping I'll loan them a few bucks?